Chemical heating pad



Oct. 11, 1938. w. H. H. DAVIS ET AL 2,132,681

CHEMICAL HEATING PAD Filed June 27, 1938 INVENTQRS W/M/AM H H [M W5LEO/V nmezn B Y 244 ATTORNEY Patented Oct. 11 1 938 UNITED STATES PATENTOFFICE CHEMICAL HEATING PAD William H. H. Davis and Leon Markel, SanFrancisco, Calif., assignors to United States Appliance Corporation, SanFrancisco, Calii., a corporation of California Application June 27,1938, Serial No. 216,022

7 Claims.

. Small chemical heating devices intended to be used to generate apredetermined amount of heat, and then to be discarded, have come intowide commercial use for the purpose of permanently waving hair. Asdisclosed in Reynolds applicationSerial No. 176,229, entitled Chemicalheating pad for permanent hair waving, one type of device for thispurpose makes use of an inner flexible assembly, consisting of sheets ofabsorbent material in contact with one or more sheets of aluminum foil.At the time the pad is used 5 the inner. assembly is saturated with achemical solution capable of exothermic reaction with the aluminum foil,and as applied to the wound hair the inner assembly is enclosed within aprotective wrapper. One characteristic of such a chemical :5 D d is thatall of the water soluble chemical supplied for the reaction, iscontained within the applied chemical solution. The pad assembly'contains no reactive chemical whatsoever, except the aluminum foil, andtherefore it is totally inert 0 before the solution is applied.

' It is an object of the present invention to provide a chemical pad ofthe above character, improved particularly with respect to the manner offorming the protective wrapper, whereby application of the chemicalsolution and use of the pad is greatly facilitated.

A further object is to improve upon the manner in which the materialforming the outer wrapper is applied to the inner assembly, to form aself to retaining envelope, without the use of adhesive or supplementalretaining means.

Further objects of the invention will appear from the followingdescription in which the preferred embodiment of the invention has beenset 5 forth in detail in conjunction with the accompanying drawing.

Referring to the drawing:

Fig. 1 is a. perspective view illustrating the parts of our pad, in itspreferred form, before folding m of the same.

Fig. 2 illustrates the. parts of our pad construc posed between thesheets of paper.

end edges of the wrapper, and Fig. 4 illustrates a second foldingoperation, whereby there is produced an envelope enclosing the innerassembly.

Fig. 5 is a perspective .view illustrating the assembly of Fig. 4 whilea predetermined amount 5 of chemical solution is being applied.

Fig. 6 is a cross-sectional detail on an enlarged scale taken along theline 66 of Fig. 4.

Fig. 7 is a side elevational view illustrating the complete pad with theflap of the envelope closed.

Fig. 8 is an enlarged cross-sectional view simi lar to Fig. 6, butillustrating a modification.

Fig. 9 is a side elevational view partly in crosssection illustratingthe manner in which my pad can beused in a permanent hair wavingoperation.

The pad construction as illustrated in the drawing consists generally ofan inner assembly I0, together with an outer wrapper l I. The innerassembly Ill can be formed as disclosed and claimed in co-pendingapplication Serial No.

' 210,436, filed May 27, 1938. Briefly, a suitable construction for theinner assembly i0 can consist of a plurality of sheets of absorbentasbestos paper lilb with'sheets I00 of aluminum foil inter- Thesuperposed sheets are passed through a suitable perforating appliancewhereby perforations [2 are formed'over the entire area of the sheets,in order to facilitate reaction of chemical solution with the aluminumfoil, and in order to facilitate ready absorption of chemical solution.

The outer wrapper ll preferably consists of a sheet l3 of metal foil,having its inner surface covered by the parchment or wax paper It.Interposed between the outer wrapper Ii and the inner assembly Hi weprefer to employ a sheet it of absorbent paper, such as paper towelling.

In manufacturing pads in quantities the parts just described can besuperposed as illustrated in Fig. 1. The next operation is to fold boththe fiat inner assembly Ill, and the outer wrapper I l,

along the common fold line [1. After making this fold the parts appearas illustrated in Fig. 2.

The next operation serves to fold over the projecting end margins I8, inorder to form the outer wrapper into an envelope enclosing the foldedinner assembly Ill. To produce a construction as illustrated in detailin Fig. 6, we use a double folding operation, that is, the end marginsl8 are folded over at least twice The first folding oporation can bealong the fold lines.l9, as illustrated in Fig. 3, and the next foldingoperation can be along the fold lines 2|, to produce a completedassembly such as illustrated in Fig. 4. Thereafter the projecting flap22 can be closed by 56 folding down on the fold line 23, to produce thefinal marketable assembly packet as illustrated in Fig. 7.

Instead of using such a double fold for the end margins l9, thesemargins can be rolled upon themselves as indicated at 24 in Fig. 8.Whichever method is employed there is formed, as previously pointed out,an envelope from the outer wrapper, and this envelope can be opened topermit access to the inner assembly, by swinging open the projectingflap 22.

The pad is used with a chemical solution capable of exothermic reactionwith the aluminum foil. It is desirable to employ a chemical'solutioncontaining a copper salt like copper sulphate, together with anoxidizing agent such as sodium chlorate, a salt like aluminum sulphatecapable of speeding up the reaction, and a salt like ammonium chloridecapable of controlling the hydrogen ion concentration of the solutionduring the reaction, whereby when the reaction is completed theremaining solution is substantially neutral. One solution which can beemployed is as follows:

Grams Hydrated copper sulphate 3 Sodium chlorate 17 Hydrated aluminumsulphate /2 Ammonium chloride--. /2 Sufficient water to make 30 cc. ofsolution.

tially as illustrated in Fig. 5, and by applying manual pressure to thetwo end edges of the pad, the folded side portions Illa. of the innerassembly ID are bulged apart. A given amount of the chemical solution isnow introduced into a suitable measuring appliance, such as asyringeili, and the nozzle of this syringe is then introduced into theopen edge of the pad between the side portions lBa of the innerassembly, and the solution then discharged into the pad. The firsteffect is to somewhat flood the interior of the pad, but in a relativelyshort interval the solution is taken up by the absorbent material of theinner assembly I0, whereby the solution is broughtinto intimate reactivecontact with all exposed surfaces of the aluminum foil. The distendedsides of the pad are then forced together and after closing down theflap 22, the pad is bent over a curler 21 upon which hair has been wound(Fig. 9). As will be understood by those skilled in the art this curlermay be mounted upon a suitable protector 28. The strand of hair isusually moistened with a suitable Waving solution before the pad isapplied, and the pad can be retained in place by a suitable-spring clip29.

During a waving operation and as the exothermic reaction proceedsbetween the chemical solution and the aluminum foil of the innerassembly ill, some water vapor is generated within the pad, and must bepermitted to escape in order to avoid internal pressure and resultantbulging. With our construction such vapor may escape from differentportions of the pad, as for example,

from the folded or rolled end margins I8, although the pad is adequatelyclosed with respect to escape of chemical solution. This is because theinterposed sheet |6 of absorbent paper enables escape of vapor, withouthowever permitting escape of liquid Any liquid tending to escape or seepfrom the inner assembly lkisabsorbedby-thepaper- 16.

It is desirable to employ asbestos paper in constructing the innerasembly ill, in order to avoid a fire hazard. Such a fire hazard isinvolved not only because of the use of an oxidizing reagent in thechemical solution, but also because in the event a pad is notimmediately applied to the hair, after solution is introduced into thesame, excessive internal heat attained can not seriously burn or charthe inner asembly. The relatively small amount of cellulose fiberafforded by the paper towelling IE, or by the parchment liner I4, isinsufilcient to cause any appreciable amount of charring or fire hazard.

In addition to the attributes described above, the double foldingdescribed, or the rolling of the end margins l8, makes it unnecessary toemploy additional retaining means to hold the wrapper intact while thepad is being shipped and used. In other words such a constructionaffords a stiil'ness for the end edges of the wrapper, and a type ofclosure for the end edges which will remain intact while the pad isbeing handled and while the flap 22' is being opened and closed.

- The construction of the pad, which affords an open longitudinal edge,for introduction of the solution as described above, is desirable fromthe standpoint of convenience of operation. Also as previouslymentioned. because such introduction of chemical solution causes initialflooding of a Part of the aluminum foil. Such initial flooding has beenfound advantageous in initiating chemical reaction between the chemicalsolution and the aluminum foil.

We claim:

1. In a chemical heating pad for permanent hair waving operations, anouter protective envelope having a closure flap and an open longitudinaledge closed by folding down the flap, and an inner assembly within theenvelope adapted to be moistened with a chemical solution for anexothermic reaction, said assembly being accessible for introduction ofsolution through said open longitudinal edge.

2. In a chemical heating pad for permanent hair waving operations, anouter protective envelope having a closure flap and an open longi:-tudinal edge closed by folding down the flap upon the body of theenvelope, and an inner assembly within the envelope adapted to bemoistened with a chemical solution for an exothermic reaction, saidinner assembly. consisting of sheets of absorbent material in intimatecontact with sheets of metallic foil, said metallic foil being adaptedfor exothermic reaction with chemical solution.

3. In a chemical heating pad for permanent hair waving operations, anouter protective envelope having a closure flap and a longitudinal openedge closed by folding down the flap upon the body of the envelope, andan inner assembly within the envelope adapted to be moistened with achemical solution applied through said open edge, said chemical solutionbeing capable of an exothermic reaction with said inner assembly, saidinner assembly consisting of a sheet of absorbent material in intimatesurface to surface contact with a sheet of metallic foil, the metallicfoil being capableof exothermic reaction with chemical solution, saidassembly being relatively flat and folded upon itself.

4. In a chemical heating pad for permanent hair waving operations, anouter protective envelope having a closure flap extending from onelongitudinal edge of the same, said longitudinal edge of the envelopebeing "open when the flap is extended and closed by folding down theflap upon the body of the envelope, the opposite parallel longitudinaledge of the envelope being closed, an inner assembly within the envelopeadapted to be moistened with a chemical solution for carrying out anexothermic reaction, the open longitudinal edge of the envelope enablingapplication of said solution, said inner assembly including a sheet ofabsorbent material in intimate contact with a sheet of aluminum foil,both said sheets forming a substantially flat assembly, with the sheetsdoubled upon themselves, said assem-' bly being disposed within theenvelope with its fold line disposed adjacent the closed longitudinaledge of the envelope and with the other longitudinal edge of theassembly substantially coincident with the open edge of the envelope.

5. In a chemical heating pad for permanent hair waving operations, aninner relatively flat assembly consisting of sheets of absorbentmaterial together with sheets of metallic foil, said sheets being inintimate surface to surface contact, the absorbent material beingadapted to be moistened with a chemical solution capable of exothermicreaction with the metallic foil, a protective wrapper sheet folded aboutsaid assembly, the wrapper being folded first over one longitudinal edgeof the assembly, the end edges of the wrapper being folded at leasttwice to form an envelope, and the remaining flap being foldable overthe assembly to form the completed wrapper.

6. In a chemical heating pad for permanent hair waving operations, aninner assembly capable of being moistened with chemical solution forcarrying out an. exothermic reaction, said inner assembly beingsubstantially flat and rectangular in contour and consisting of a sheetof absorbent material together with a sheet of metallic foil in intimatesurface to surface contact with the absorbent material, the metallicfoil being capable of exothermic reaction with the chemical solution,and a protective wrapper sheet disposed about the inner assembly, saidwrapper consistin contour and consisting of a sheet of absorbentmaterial together with a sheet of metallic foil in intimate surface tosurface contact with the absorbent material, the metallic foil beingcapable of exothermic reaction with the chemical solution, and aprotective wrapper sheet disposed about the inner assembly, said wrapperconsisting of a sheet of flexible material rectangular in contour beforebeing folded, and folded about the infier assembly to form an envelopehaving an extending flap to close over one longitudinal edge of theenvelope, the end edges of the envelope being formed by rolling thematerial of the wrapper upon itself, thereby forming a substantiallyself sustaining envelope.

' WM. H. H. DAVIS.

LEON MARKEL.

